~150-180 for classical, and I think a bit lower for Western.

Actually, if memory serves, it's possible to hold Western fountain with only 2-3 horses (perhaps a killer gallop/speed/stamina horse for reining + barrels, and then a killer dressage/stamina/speed/jumping horse for the other 3.)

I feel like getting a top TB wouldn't be too difficult to hold barrel/reining, hard to get some of the other breeds though. Specifically trot breed tbh at least if I don't want to spend passes. Maybe I think I could use the same nokota for trail/wp? but I'm not too sure, some of these breeds are really iffy to get without spending passes.

They are actually going to have to be quite a bit higher, prix is way more competitive now. This week, I ranked 52nd in western, with the following placements - 154, 28, 150, 68, 27. Based on this, you should aim for an average of 70-80 for each placement, or 2 or 3 very high placing ones, with 2 or 3 weaker ones. The more you are prepared to pay towards them, the longer they will last. I've found I drop 5 places on average per week for the overall ranking when I don't replace any of them.